I had a look at this. Appears that the problem is that there is no fileID
value in the trailer. No idea how to handle that, since the PDF spec appears
to require this value for the encryption algorithm.

I have a PDF file for which has evince disabled the "Print" menu item,
it has not asked for any password. Is it related to this bug?
How can I recognize if the PDF file is acrobat 7 file?
In properties there is this info:
...
Creator: FrameMaker 7.1
Producer: Acrobat Distiller 4.0 for Windows
...
Security: No
Format: PDF-1.5
...

I think this is what comment #4 referred to. I would like to have this bug closed and open another one, but I do now know how the pdf feature of splitting a document into many files is called. Linearized pdf? PDF reference guide did not quickly shed any light on me on this.